It is difficult, if not impossible, to compare the P4 to the D12, as the possible combinations of opamps that are available in the rolling kit will make significant differences in the SQ of the P4.
It will be possible to configure the P4 so as to sound nearly identical to the D10 Topkit, as iBasso has chosen to include the D10 Topkit L/R Class A module in the P4 rolling kit. As I stated previously, iBasso has included a really fine selection of premium audio opamps in the supplied rolling kit. The opamps in the kit will most certainly do justice to the quality of the P4 circuitry.
I think the choice between the D12 and P4 will boil down to whether or not one needs the optical, coax, and usb inputs of the D12 or would prefer the more customizable P4 and be limited to Aux input only.
For use with the more difficult-to-drive cans, or for those who choose to listen at head-banging volume levels, the P4 is probably the wiser choice.
Thanks for the reply Ron, looking forward to trying out the D12 Topkit.
The P4 amp + D12 DAC should rock most if not all the phones for sure.
Edited by gtoviper - 11/5/10 at 10:14am